Closings

Severe Weather

u local users capture midwest tornado, storm images

u Local users in Oklahoma and Kansas captured amazing tornado images and shared them on u local.

What is a tornado?Accordingto theGlossary of Meteorology(AMS 2000), a tornado is"a violently rotating column of air, pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud."

Howdo tornadoes form?The classic answer--"warm moist Gulf air meets cold Canadian air and dry air from the Rockies"--is a gross oversimplification according to NOAA.

Literally, in order for a vortex to be classified as a tornado, it must be in contact with the groundandthe cloud base.

Many thunderstorms form under those conditions (near warm fronts, cold fronts and drylines respectively), which never even come close to producing tornadoes.

NOAA says tornado formation is believed to be dictated mainly by things which happen on the storm scale, in and around the mesocyclone.

KOCO What directiondo tornadoes come from? Does the region of the US play a role in path direction?Tornadoes can appear from any direction. Most move from southwest to northeast, or west to east says NOAA.

KOCO Some tornadoes have changed direction amid path, or even backtracked.

A tornado can double back suddenly, for example, when its bottom is hit by outflow winds from a thunderstorm's core.

Some areas of the UStendto have more paths from a specific direction, such as northwest in Minnesota or southeast in coastal south Texas.

This is because of an increased frequency of certain tornado-producing weather patterns (say, hurricanes in south Texas, or northwest-flow weather systems in the upper Midwest).

Doeshail always come before the tornado? Rain?Lightning? Utter silence?Not necessarily, for any of those.

Rain, wind, lightning, and hail characteristics vary from storm to storm, from one hour to the next, and even with the direction the storm is moving with respect to the observer.

While large hailcanindicate the presence of an unusually dangerous thunderstorm, andcanhappen before a tornado, don't depend on it cautions NOAA.

The National Weather Service says hail, or any particular pattern of rain, lightning or calmness, is not a reliable predictor of tornado threat.

Sign up for severe weather email or SMS text alerts on our website from a desktop or laptop computer. Just click on "alerts" at the top of any page. We will send notifications right to your inbox or mobile device when the National Weather Service issues alerts.

How long does a tornado last?Tornadoes can last from several seconds to more than an hour.

The longest-lived tornado in history is really unknown by NWS, because so many of the long-lived tornadoes reported from the early-mid 1900s and before are believed to be tornado series instead.

KMBC The National Weather Service (NWS) says most tornadoes last less than 10 minutes.

Big fat tornadoes are the strongest ones, right? Not necessarily. According to NOAA, there is a statistical trend (as documented by NSSL's Harold Brooks) toward wide tornadoes having higher damage ratings.

This could be related to greater tornado strength, more opportunity for targets to damage, or some blend of both. However, the size or shape ofany particular tornadodoes not say anything conclusive about its strength.

What does a tornado sound like?That depends on what it is hitting, its size, intensity, closeness and other factors.

The most common tornado sound is a continuous rumble, like a nearby train. Sometimes a tornado produces a loud whooshing sound, like that of a waterfall or of open car windows while driving very fast.

Check out the Prepare section of Tornadoes smartphone mobile app to learn more. The "Tornadoes" app is available in iTunes or GooglePlay for free.

Sign up for severe weather email or SMS text alerts on our website from a desktop or laptop computer. Just click on "Alerts" at the very top of any page to sign up for free notifications.

Comments

The views expressed are not those of this site, this station or its affiliated companies. By posting your comments you agree to accept our terms of use.